These cells were purchased for the purposes of testing with donations made for that purpose. Thank you! To prevent any confusion with the eGo-type "batteries", I use the term "cell" here to refer to a single 18650, 26650, etc.
Disclaimer
The statements, conclusions, and recommendations I make based on these tests are only my personal opinion. Carefully research any battery you are considering using before purchasing.
Testing cells at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved and how to minimize them.
A note regarding current ratings and my testing
If the cell has only one current rating number on it, or if it says "max discharging current" then I have to assume that the company is stating that the cell can be discharged at that current level in any way, including continuously.

Bottom Line
This is a great 25A continuous cell that meets its 2000mAh rating. It did better than the last time I tested it in June 2015. The HD2 and VTC4 are close in overall performance and I don't think you'd see a difference in actual use.
Continuous-Current Test Results

Pulsed-Current Test Results
These tests are done to show the performance of the cell at higher pulsed current levels. If you are running your mod at these levels be aware that you risk overheating, and possibly venting, the battery if there is a malfunction or accidental pressing of your mechanical mod's button.

Comments
List of Battery Tests | E-Cigarette Forum
18350 Safety Grades and Pulse Performance Data | E-Cigarette Forum
18650 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum
Disclaimer
The statements, conclusions, and recommendations I make based on these tests are only my personal opinion. Carefully research any battery you are considering using before purchasing.
Testing cells at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved and how to minimize them.
A note regarding current ratings and my testing
If the cell has only one current rating number on it, or if it says "max discharging current" then I have to assume that the company is stating that the cell can be discharged at that current level in any way, including continuously.




Bottom Line
This is a great 25A continuous cell that meets its 2000mAh rating. It did better than the last time I tested it in June 2015. The HD2 and VTC4 are close in overall performance and I don't think you'd see a difference in actual use.
Continuous-Current Test Results

Pulsed-Current Test Results
These tests are done to show the performance of the cell at higher pulsed current levels. If you are running your mod at these levels be aware that you risk overheating, and possibly venting, the battery if there is a malfunction or accidental pressing of your mechanical mod's button.


Comments
- At 10A continuous it reached over 1850mAh. This is good performance for an 2000mAh-rated cell operating at 10A so I am rating this cell at 2000mAh.
- Its temperature at 15A continuous was 63°C, significantly below the average for a cell operating at its continuous discharge rating (CDR).
- At 20A continuous the temperature rose to 74°C, a bit below the average for a cell operating at its CDR.
- At 25A continuous the temperature rose to 83°C. This is the upper limit of the range of average temperatures for a cell operating at its CDR.
- At 30A continuous the temperature rose to 95°C. This is much too hot for a cell operating at its CDR. The voltage is starting to sag a lot more too, indicating that the cell is operating at beyond its rating.
- Two more discharges at 30A continuous showed some signs of damage. This is clearly only a 25A cell.
- I am setting a CDR of 25A for this cell since at this current level its operating temperature is at upper limit of the average for a cell operating at its CDR. While operating any cell near its rated maximum current level causes damage to the cell, I would expect decent cycle life from this cell at 25A continuous.
- I have included pulsed discharges but I haven't set pass/fail standards for pulse testing yet. The discharges were done at 5sec on/30sec off, down to 2.5V. One chart shows the entire discharge at each level. The other chart is zoomed in to show the first 5 minutes to make it easier to see the voltage sag at different current levels.
List of Battery Tests | E-Cigarette Forum
18350 Safety Grades and Pulse Performance Data | E-Cigarette Forum
18650 Battery Ratings -- Picking a Safe Battery to Vape With | E-Cigarette Forum
26650 Safety Grades and Pulse Performance Data | E-Cigarette Forum
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